Animation is a booming business for Hollywood, which produces about a dozen cartoon films a year, including 2012 global box office drivers like "Ice Age: Continental Drift" and "Madagascar 3: Europe's Most Wanted."

But the fields of film and television animation have long been divided by stark lines, with little room for talent to move between the two media.

That's changing this year, as three directors with roots in TV are helming major studio animated movies: Genndy Tartakovsky, the director of Sony Pictures Animation's "Hotel Transylvania" created the Cartoon Network series "Dexter's Laboratory," "Samurai Jack" and "Star Wars: Clone Wars"; Mark Andrews, who made Pixar's "Brave," storyboarded on the shows "Osmosis Jones," "Star Wars: Clone Wars" and "Samurai Jack"; and Rich Moore, who directs Walt Disney Animation Studios' upcoming video game comedy, "Wreck-It Ralph," worked on such shows as "The Simpsons," "The Critic" and "Futurama."

In recent years, tautly written animated TV shows have attracted an adult audience, according to Tom Sito, adjunct professor of animation at USC.

"TV animation has gotten very sophisticated," Sito said, citing shows like "The Simpsons." "There's so much strong animation being done in TV that it's attracting film studios' notice."

Animation directors who work in TV are accustomed to brisker schedules and tighter budgets, which can make them attractive problem solvers in the world of features. Both Tartakovsky and Andrews came aboard projects that had already seen directors come and go, and were charging toward a release date.

"In TV you don't have any time to play around with stuff," said Andrews. "Every eight weeks or so, your episode has to be done. For me, that was a fantastic training ground. I learned to go with my gut. You're built for crisis from the beginning."